




















tCH_{3}HC=CHCl 


PDF 













Chlorine 



Nuclear
Quadrupole Coupling Constants 



in trans1Chloropropene 

































Calculation of the chlorine
nqcc's in trans1chloropropene was made on a molecular
structure derived ab initio, as described
below. These are compared with the experimental nqcc's of Beaudet [1]
in Table 1. Structure parameters are given
in Zmatrix format in Table 2. 












In Table 1, RMS is the root mean square difference
between calculated and experimental diagonal nqcc's (percentage of the
average of the magnitudes of the experimental nqcc's). RSD is the
calibration residual standard deviation for the B1LYP/TZV(3df,2p) model
for calculation of the chlorine nqcc's. 












Subscripts a,b,c refer to the
principal axes of the inertia tensor; x,y,z to the principal axes
of the nqcc tensor. The nqcc yaxis is chosen coincident with the
inertia caxis, these are perpendicular to the molecular symmetry plane.
Ø (degrees) is the angle between its subscripted
parameters. ETA = (X_{xx}  X_{yy})/X_{zz}. 































Table 1. Chlorine
nqcc's in t1Chloropropene, conformer I (see below) (MHz). 













Calc. 

Expt. [1] 










^{35}Cl 
X_{aa} 
 
60.67 
 
60.3 



X_{bb} 

28.88 

28.7 



X_{cc} 

31.79 

31.6 



X_{ab} 

31.13 













RMS 

0.3 (0.75 %) 





RSD 

0.49 (1.1 %) 













X_{xx} 

38.63 





X_{yy} 

31.79 





X_{zz} 
 
70.43 





ETA 
 
0.097 





Ø_{z,a} 

17.40 





Ø_{a,CCl} 

17.20 





Ø_{z,CCl} 

0.20 












^{37}Cl 
X_{aa} 
 
47.86 





X_{bb} 

22.80 





X_{cc} 

25.06 





X_{ab} 

24.47 













RSD 

0.44 (1.1 %) 


































Cl is trans with respect
to CH_{3}. Within the framework of C_{s} symmetry,
one methyl H lies in the plane of symmetry, one above and one below the plane.
With respect to the C(1)C(2)C(3) backbone, the inplane H may be trans
(conformer I) or cis (conformer II) with Cl. Calculation was made on
both structures. At the B1LYP/TZV(3df,2p) level of theory, E_{I}
< E_{II} by 2.0 kcal/mol. The calculated nqcc's shown
in Table 1 are for conformer I, for which the RMS difference between calculated
and experimental nqcc's is 0.3 MHz. For conformer II, calculated X_{aa},
X_{bb}, and X_{cc} are respectively 60.76, 28.95,
and 31.80 MHz. The RMS difference is, as above, 0.3 MHz. 






















Molecular Structure 












The molecular structure
was optimized at the MP2/6311+G(d,p) level of theory assuming
C_{s} symmetry. The optimized CC bond lengths, single
and double, were corrected using equations obtained from linear
regression analysis of the data given in Table IX of Ref.[2]. For
the CCl bond, the structure was optimized at the MP2/6311+G(2d,p)
level and corrected by linear regression analysis of the data given
in Table 4 of Ref.[3]. The CH bond lengths were corrected using
r = 1.001 r_{opt}, where r_{opt} is obtained by MP2/631G(d,p)
optimization [4]. Interatomic angles used in the calculation
are those given by MP2/6311+G(d,p) optimization. 





















Table 2. ZMatrix (Å and degrees). 










H 








C 
1 
R1 






C 
2 
R2 
1 
A3 




C 
2 
R3 
1 
A4 
3 
180. 


Cl 
4 
R4 
2 
A5 
3 
180. 


H 
4 
R5 
2 
A6 
3 
0. 


H 
3 
R6 
2 
A7 
6 
D1 


H 
3 
R7 
2 
A8 
6 
D2 


H 
3 
R7 
2 
A8 
6 
D2 












Conformer I 

Conformer II 












R1 
1.0845 

1.084 



R2 
1.4945 

1.5035 



R3 
1.329 

1.329 



R4 
1.726 

1.726 



R5 
1.082 

1.082 



R6 
1.090 

1.088 



R7 
1.0915 

1.091 



A3 
118.28 

118.87 



A4 
119.04 

118.56 



A5 
123.06 

123.00 



A6 
123.36 

123.47 



A7 
111.27 

110.54 



A8 
110.71 

111.45 



D1 
0. 

180. 



D2 
120.40 

60.29 

























[1] R.A.Beaudet, J.Chem.Phys. 37,2398(1962). 


[2] J.Demaison, J.Cosléou, R.Bocquet,
and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994). 


[3] I.Merke, L.Poteau, G.Wlodarczak, A.Bouddou,
and J.Demaison, J.Mol.Spectrosc. 177,232(1996). 


[4] J.Demaison and G.Wlodarczak, Structural
Chem. 5,57(1994). 






















H_{2}C=CHCl 
H_{2}C=CFCl 
cClHC=CHCl


cFHC=CHCl 
tFHC=CHCl 
H_{2}C=CCl_{2} 

H_{2}C=CClCN 
F_{2}C=CHCl 
F_{2}C=CCl_{2} 

(CH_{3})_{2}C=CHCl 
Cl_{2}C=CHCl 
F_{2}C=CFCl 

CH_{3}ClC=CH_{2} 
cCH_{3}HC=CHCl 
CH_{2}ClHC=CH_{2} 

cCH_{3}FC=CHCl 























Table of Contents 





Molecules/Chlorine 






























t1ClPropene.html 






Last
Modified 16 June 2004 









